Over
the past three years Intel has made Celeron processors evolve into a
mature alternative for affordable but powerful PCs, by adding a welcome
128 KB second level cache memory and more recently a long desired 100MHz
frontside bus to boost performance as well as some other neat
enhancements. The Intel Celeron 900MHz is the latest incarnation of the
Intel Celeron family. This new model doesn’t bring any architecture
enhancements: the only plus over the previous 850MHz model is the
increased frequency. This new Celeron 2 from Intel is in fact a light
version of Coppermine series of CPUs that uses the P6 micro architecture:
The Celeron 900MHz now shares the same SSE instructions set as the Pentium
III, uses a 100MHz FSB, is equipped with 128 KB of second level cache
memory, is now engraved using 0,18µ technology and comes in a FC-PGA
Socket 370 Form Factor. This new FC-PGA format is supposed to be more
adapted to high frequencies today processors offer and is cheaper to
produce. Pentium III and Celeron CPUs now look exactly the same, only the
markings differ. During our tests the Celeron 900MHz didn’t heat a lot: it
only reaches the maximum temperature of 87.8 F (31.0° Celsius) after
intensive use, demonstrating good resistance when users overclock it.

Some Celeron Processors

Like the Pentium III processor, the Celeron 2 comes with Dynamic Execution
Technology to enhance further performance with three distinct features.
The Multiple Branch Prediction predicts program execution through several
branches; accelerating the flow of work to the processor while the
dataflow Analysis creates an optimized, reordered schedule of instructions
by analyzing data dependencies between instructions. Finally the
speculative execution unit carries out instructions speculatively and
based on this optimized schedule, ensures that the processor’s superscalar
execution units remain busy, boosting overall performance.

Intel Celeron 900MHz
Processor (click to enlarge)

Thanks to the 0,18µ
technology the Celeron heats less than before and so its voltage has been
changed from 2 to 1.6 volts. The Celeron 900MHz fully supports MMX
extensions: Intel MMX technology includes instructions
and data types that allow applications to achieve a new level of
performance. Intel’s MMX technology is designed as a set of basic,
general-purpose integer instructions that are easily applied to the needs
of a wide diversity of multimedia and communications applications. The
highlights of the technology are: Single Instruction, Multiple Data (SIMD)
technique, 57 new instructions, Eight 64-bit wide MMX technology
registers, and four new data types. Adding SSE instructions to the Celeron
2 is a good thing since those instructions will complete the MMX ones to
boost some operations with games or applications that use the Direct X
APIs from Microsoft. SSE instructions are especially dedicated to enhanced
overall 3D performance.

One thing is very important
in the architecture of every processor: the cache memory. For memory, the
cache memory stores the most used instructions or data to speed up
operations and reduces computing delays. The Celeron 900 MHz comes with 16
KB of data and another 16 KB instructions L1 cache. The L1 cache memory
ensures that the CPU is always fed with data so it really has a
significant impact on performance. Also included with the Celeron 900 MHz
is an on-die 128 KB 4 way associative L2 cache (against 256 KB 8 way
associative for Pentium III) clocked at the CPU full speed that is to say
900 MHz and connected to it through a 256-bit bus. First Celeron used a
64-bit only bus so this new 256-bit bus can convey more data in one single
clock cycle resulting in better performances, once again.